院报 ›› 2017, Vol. 34 ›› Issue (12): 73-77.DOI: 10.11988/ckyyb.20160904

• 岩土工程 • 上一篇    下一篇

南宁软岩地基大直径灌注桩极限承载力预测

江杰1a, 1b, 2, 陈骏1a, 肖萌1a, 韦永超3, 马少坤1a, 1b, 2   

  1. 1. 广西大学 a.土木建筑工程学院;b.广西防灾减灾与工程安全重点实验室,南宁 530004;
    2.桂林理工大学 广西岩土力学与工程重点实验室,广西 桂林 541004;
    3.中国市政工程西北设计研究院有限公司,兰州 730000
  • 收稿日期:2016-09-05 出版日期:2017-12-01 发布日期:2017-12-22
  • 作者简介:江杰(1979-),男,湖北麻城人,教授,硕士生导师,博士后,主要从事岩土地下工程的教学与研究工作,(电话)18878884176(电子信箱)jie_jiang001@126.com。
  • 基金资助:
    国家自然科学基金项目(51568006,41362016); 中国博士后科学基金项目(2017M612865); 广西重点实验室系统性研究项目(2016ZDX11);广西岩土力学与工程重点实验室资助课题(14-KF-03,13-KF-02); 广西博士后专项资助项目

Prediction of Ultimate Bearing Capacity of Bored Pile of LargeDiameter in Soft Rock Foundation in Nanning

JIANG Jie1, 2, 3, CHEN Jun1, XIAO Meng1, WEI Yong-chao4, MA Shao-kun1, 2, 3   

  1. 1.College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, China;
    2.Guangxi Key Laboratory of Disaster Prevention and Engineering Safety, Guangxi University, Nanning 530004, China;
    3.Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering, Guilin University ofTechnology, Guilin 541004, China;
    4.CSCEC AECOM Consultants Co.,Ltd., Lanzhou 730000,China
  • Received:2016-09-05 Online:2017-12-01 Published:2017-12-22

摘要: 南宁市下伏泥岩粉砂岩地基具有显著的浸水崩解软化特性,使得该地基大直径灌注桩承载力难以确定。依托南宁市火车东站南广场高架平台工程软岩互层地基大直径灌注桩项目,对该工程2根群桩基桩进行了静载试验研究。针对试验中试桩未达到破坏其极限承载力难以确定问题,采用指数函数拟合法和数值反演分析法来预测其荷载沉降性状和极限承载力,并进行对比分析。结果表明:软岩互层地基桩基荷载沉降性状为缓变型,表现出端承摩擦桩的特性,可用指数函数来描述试桩受荷性状,并结合数值反演分析来预测其极限承载力,目前常用的桩基设计方法低估了该地基中基桩的承载力。

关键词: 灌注桩, 静载试验, 极限承载力预测, 指数模型, 数值反演分析

Abstract: The bearing capacity of cast-in-place bored pile of large diameter in soft rock foundation in Nanning is difficult to determine due to softening and disintegration characteristics when soaked in water. Static load test was conducted to determine the bearing capacity of bored pile in the soft rock interbedding foundation of an elevated platform project in the railway station of Nanning Ciy. Both exponential function fitting method and numerical back analysis were used to accurately predict the load-settlement relation and ultimate bearing capacity of test pile which did not reach the ultimate state. Results show that the load-settlement curve of bored pile in soft rock interbedding foundation is an adjustment curve and the pile works as end bearing friction pile. As common design methods of pile foundation at present underestimates the bearing capacity of pile in this foundation, exponential function which is used to describe the load-settlement behaviour of test pile and numerical back analysis can be combined to estimate the ultimate bearing capacity of test pile.

Key words: bored pile, static load test, prediction of ultimate bearing capacity, exponential model, numerical back analysis

中图分类号: 

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